RE: [cygwin] Re: `CYGWIN=winsymlinks:nativestrict`, `ln -s target link` fails if target doesn't exist

["Jason Pyeron" <jpyeron at pdinc dot us>]

> -----Original Message-----
> From: Peter Rosin
> Sent: Friday, April 29, 2016 8:03 AM
> 
> On 2016-04-29 13:34, Gene Pavlovsky wrote:
> >>> POSIX says a symlink to a missing target is perfectly 
> well-defined 
> >>> (you can't stat() through it, but you can readlink() it). But 
> >>> Windows native symlinks can't do that.  So the problems you are 
> >>> encountering all stem from the fact that you are trying 
> to make Windows do something it can't.
> >>
> >> My initial reaction was that, too, but I tried mklink (CMD 
> internal 
> >> command)
> >>
> >>> mklink x y
> >>
> >> and it created the symlink in the empty directory just fine.
> > 
> > This is my point exactly. Windows dangling symlinks can be 
> created as 
> > easily as in UNIX.
> > At least this is the case on my Win7 x64.
> 
> No, it can't.
> 
> c:\>mklink a b
> c:\>mkdir b
> c:\>cd b
> c:\b>cd ..
> c:\>cd a
> The directory name is invalid
> c:\>rmdir b
> c:\>echo hello > b
> c:\>type a
> hello
> 
> It only works for dangling links to files. Not good enough.

To be more precise, you must choose file or dir symlinks at cretion time:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Windows\system32>cd C:\cygwin\tmp\winlinktest\dirs

C:\cygwin\tmp\winlinktest\dirs>mklink /D a b
symbolic link created for a <<===>> b

C:\cygwin\tmp\winlinktest\dirs>mkdir b

C:\cygwin\tmp\winlinktest\dirs>cd b

C:\cygwin\tmp\winlinktest\dirs\b>cd ..

C:\cygwin\tmp\winlinktest\dirs>cd a

C:\cygwin\tmp\winlinktest\dirs\a>cd ..

C:\cygwin\tmp\winlinktest\dirs>rmdir b

C:\cygwin\tmp\winlinktest\dirs>echo hello > b

C:\cygwin\tmp\winlinktest\dirs>type a
Access is denied.

C:\cygwin\tmp\winlinktest\dirs>del b

C:\cygwin\tmp\winlinktest\dirs>mkdir b

C:\cygwin\tmp\winlinktest\dirs>cd a

C:\cygwin\tmp\winlinktest\dirs\a>

Jason Pyeron

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